dodge



Oct. 16, 1945 A; Y. DODGE Re. 22,682 CLUTCH Original Fil ed lay 13, 1940 2 sh eets sheet 1 u vvsm'oh ATTORNEYS.

ills-5E5;

Reissued Oct. 16, 1945 v Re. 22,682-

cw'ron Adiel y. Dodge, Rockford, 111. Original No. 2,355,710, dated August 15, 1944, Se-

rial No. 334,706, May 13, 1940. Application for reissue July 11, 1945, Serial No. 004,412

11 Claims.

This invention relates to clutches and more particularly to clutches whose engagement and disengagement is controlled in response to speed.

One of the objects of the invention is to provide a clutch whoseengagement is controlled by centrifugal weights connected to the clutch enaging members to operate the same. The weights are preferably connected to the clutch members through a linkage so as to operate the members in accordance with a function of the centrifugal force of the weights.

Another object of the invention is to provide a speed responsive clutch whose engagement and disengagement will occur at different speeds.

Another object of the invention is to provide a speed responsive clutch which may be held out of engagement manually when desired.

Still another object of the invention is to provide a speed responsive clutch for connecting two shafts whose engagement is controlled in accordance with the speed of a third shaft or rotating member.

While there have been numerous automatic clutches responsive to centrifugal force proposed,

none of these has been entirely satisfactory for all driving conditions. Where a centrifugal clutch is desired to engage and handle a considerable amount of torque at low speeds, the amount of weight required acting directly on the friction members is excessive. Therefore, it becomes desirable to devise weights which have a large mechanical advantage thereby multiplying the centrifugal force to attain a large force for actuating the frictionmembers.

To further reduce the necessity of excessive weight, I have incorporated a self-actuating feature in the friction member design, so that the tangential friction load on the clutch members tends to cause the friction member to engage rather than disengage.

In addition to the above, I have provided a link between the weight and the friction member which imparts relatively rapid movement to the friction shoe members during the first partof their movement to quickly take up clearance during which movement the angle of the linkage changes in such a way as to increase the mechanical advantage of the weight acting to engage the friction shoe member. 'This accomplishes two things. In addition to increasing the application force at the time needed, it permits the weight to assume a position further from the 4 center, thus increasing the centrifugal force generated thereby. In order to provide a more simple and rugged structure, I pivot the centrifugal actuating weights upon the same pins which act as anchor pins for the friction shoe' members. This both simplifies the structure and acts in a manner to support the anchor pins since the combined force imposed by the weights and its linkage is in a large degree opposed to the force imposed upon the pin by the opposite shoe member when transmitting torque.

Inherent to all centrifugally actuated clutches there exists a tendency to produce excessive slip under the conditions of slowly increasing speed above the predetermined speed at which they engage. If the device in question has a tendency to be deceierated by the engagement of the.

clutch behind a hydraulic drive unit. This location may be preferred in order to reduce the revolving mass ahead of the gears which are to be shifted, when the friction clutch is disengaged. When an automatic clutch of the usual type,

which is responsive to the speed of the driving,

clutch element is so placed, its response to some predetermined speed of rotation is upset due to slip which takes place in the hydraulic unit. This is objectionable because both the hydraulic unit and the friction clutch slip, this increasing the total amount of slip.

To overcome this objection I have produced an, automatic clutch responsive to centrifugal force suitable for locating backof a hydraulic 'unit which does not have the objectionable characteristics aforementioned. In my clutch the governing centrifugal weights turn at engine speed. Therefore, any slip which takes place in the hydraulic unit has no effect upon their action.

The above and other objects, advantages and novel features of the invention will be apparent from the following description of the accompanying drawings, in which:

Figure 1 is an end view of a clutch embodying the invention with parts omitted;

Figure 2 is a partial axial section of Figure 1; and

Figure 3'is a side elevation with parts in section of another clutch embodying the invention In Figures 1 and 2 the clutches are shown connecting two'shafts III and I2 and comprises a. friction drum ll connected to the shaft ill and having an axial flange it. A plate i8 secured; to the shaft l2 closes the drum l6 and carries a pair of pivot pins 20 and 22 on which friction engage the flange l8, and are pivoted at one end on each of the pins 22 and 20. respectively.

The friction shoes are operated by weights Ill and I2 pivoted respectively on the pins 22 and 20. Theweight I! is connected adjacent the pin 22 by links 3| with the free end of the friction shoe 2!, and the weight is similarly conv nected by links 38 to the free end of the shoe 2.

mum speed before it is subjected to any load. The construction of Figure 3 is particularly adapted for this purpose.

As shown, a shaft 80 to be-driven carries a drum 82 whichmay be engaged by friction shoes 64 carried by a plate 6| on the shaft 58. The construction of the shoes 04 is not shown in detail,

but it may be the same as that illustrated in Figure 1.

The shoes are guided by guide projections 68 carried by the plate 68 and may be pivoted to the plate in the manner of the shoes of Figure. l.

urge them into tighter engagement with the flange to provide positive driving connection, but if the flange tends to turn in the opposite direction the shoes will grip it with a smaller force.

In order to hold the shoes normally out of engagement with the flange a collar 38 is slidably mounted on the shaft l0 and is connected by links 40 with projections 42 on the weights Ill and 32. The collar is urged to the right as seen in Figure 2 through a plate 44 engaging the collar through a suitable bearing and slidably carried by pins 4 extending through the'drum II. A coil spring 48 engages the plate 44 to urge'it to the right. p

Movement of the collar 44 to the right tends to move the links 40 toward a radial position and acts on the projection 42 to draw the weights l0 and I2 inwardly. As centrifugal force on the weights increases they will be thrown outwardly to move the collar N to the left against the spring 48 and to force the shoes into engagement with the drum. The weights 3' and I! may be provided with guide rollers 50 engaging the-flange II to absorb the thrust of the links Ill. Due to this arrangement, and to the fact that the links the shaft, the spring 48 exerts a larger force on the weights when collar 38 is in its right-hand position than when it has been moved to the left. Thus a higher speed is required to overcome the spring force when the shoes are out of engagement with the flange than to hold the shoes in engagement with the flange once they are engaged therewith. In this way chattering of the shoes is prevented and once they have started to move into engagement with the flange they will move into full engagement therewith.

In order that the clutch may be held in disengaged position when desired, the pins 46 are provided outside of the drum I4, with collars 52 connected by a thrust bearing. Manually controllable means, such as a yoke, may engage the outer collar 52 to press the plate 44 t the right so as to augment the force of spring 8 and to hold the clutch out of engagement, regardless of the speed of the shaft l2.

Figure 3 illustrates a similar clutch for use in connection with a variable speed driving element 54 having a driving member connected to a shaft 56 and a driven member driving a shaft 58. The driving unit 54, as shown,.may be any variable speed type unit, but is illustrated as a hydraulic coupling in which the driven member and shaft 58 are driven at variable speeds from the driving member. In connection with devices of this type it may be desirable to connect the driven member to a shaft to be driven at some predetermined speed of the driving member, for example, to permit an engine connected to the driving member to reach a predetermind mini- 40 change their angle as the collar 38 moves on I A collar ll slidable on the shaft 58 is connected to the shoes "by links 12. A coil spring 14 urges the collar to the left in a direction to move the shoes out of engagement with the drum 6!. g

The collar I0 is urged to the right to engage the shoes with thedrum by centrifugal weights I I8 eccentrically pivoted to the outer driving casing of the unit 54. The weights 18 have cam projections," pressing against bearings 80 which engage the collar III. In operation, the weights IE will respond to the speed of the driving Shaft II and will urge the collar Ill to the right to force the. friction shoes 64 into engagement with the drum 62. Thus engagement of the clutch is controlled in response to the speed of a driving member which is separate from either of the shafts to be connected by theciutch.

In order to hold the clutph out of engagement when desired, a thrust ring 82 is connected through a bearing It to the collar [0. The

thrust ring 82 may be urged to the left manually in any desired manner.

While .two embodiments of the invention have been illustrated and described in detail it will be understood that they show examples only and 'are not intended to define the scope of the invention, reference being had for this purpose to the appended claims.

' What is claimed is:

- plate carried by the other shaft, a pair of arouate friction shoes pivoted at one end on the plate and movable into engagement with the drum, 8. pair of weights eccentrically pivoted on the plate and linked to the free ends of the shoes to move them into engagement with the drum in response to centrifugal force, a collar slidable axially on one of the shafts, extensions on the weights lying on the opposite sides of radial lines through the pivot points of the weights than the weights respectively, links connecting the collar to the extensions, and resilient means urging the collar in a direction to move the weights inwardly in opposition to centrifugal force thereon.

2. A clutch for connecting two shafts comprising a drum member connected to one of the shafts, a plate carried by the other shaft, an

arcuat'e friction shoe pivoted at one end on the plate and movable into engagement, with the drum member, a collar slidable axially on one of the shafts, a link pivoted at one end to the collar, a mechanism including means pivoted to the other end of the link' for connecting said other end of the link to the free end of the fricradial as the shoe moves out of engagement with the drum,,and means acting on the collar to urge it in a direction .to disengage the shoe from the drum.

3. A clutch for connecting two shafts comprising a drum member connected to one of the shafts, a plate carried by the other shaft, an arcuate friction shoe pivoted at one end on the plate and movable into engagement with the u drum member, a weight eccentrically pivoted on the plate, a link pivotally connected at its D- posite ends to the weight and to the free end of the shoe, said link changing its angle as the weight and shoe move to increase the mechanical advantage of the weight acting on the shoe as the shoe is moved into engagement with the drum, a collar slidable axially of the shafts, a link pivotally connected to the collar and the weight in such a way that movement of the collar toward the weight moves the weight in toward the axis of the shafts, and means for moving the collar toward the weight to disengage the clutch.

4. A clutch for connecting two shafts comprising a drum connected to one of the shafts, a plate carried by the other shaft, pivot pins on the plate at diametrically opposite points, an arcuate friction shoe and a centrifugal weight pivoted on each of the pinsand extending generally toward the other pin, and links-connecting the free ends of the shoes respectively to theweights pivoted on the opposite pivot pin whereby the weights actuate the shoes and create reaction forces on the pivot pins tending to balance the pressure of the shoes thereon.

5. A clutch for connecting two shafts comprising a drum carried by one of the shafts, a supporting member carried by the other shaft adjacent the drum, a friction shoe movably mounted on the supporting member, and movable into ing a drum carried by one of the shafts, a supporting member carried by the other shaft adjacent the drum, a friction shoe movably mounted on the supporting member, a weight eccentrically pivoted on the supporting member, means connecting the weight to the Shoe to move the shoe into engagement with the drum as the weight moves out in response to centrifugal force, a spring, and mechanism operatively connecting the spring to the weight and including a link which changes its angle relative to the shaft axis as the weight moves out to give the weight an increasing mechanical advantage over the spring as the weight moves out.

'7. A clutch for connecting two shafts comprising a drum member connected to one of the shafts, a plate carried by the other shaft, pivot pins at diametrically opposite points on the plate, an arcuate friction shoe and a centrifugal weight pivoted on each of the pins'and extending generally toward the other pin, links pivotally connected at their opposite ends respectively to theweights adjacent their pivot pins and to the free ends of the shoes pivoted on the other pivot pin, said links lying at a relatively small angle to a radius through them when the shoes are out of engagement with the drum and increasing their angle as the weights and shoes move to increase the mechanical advantage ofthe weights acting on the shoes as the shoes are moved into engagement with the drum.

8. A clutch for connecting two shaftscomprising a drum carried by one of the shafts, a supporting member carried by the other shaft adjacent the drum, a friction shoe movably mounted on the supporting member, and movable into engagement with the drum in response to centrifugal force, a collar movable on one of the shafts, means including a link connecting the collar to the friction shoe, and a spring acting on the collar urging it in a direction to move the shoe out of engagement with the drum, the link being so connected that its angle relative to the spring changes to give the shoe a greater mechanical advantage over'the spring when the shoe is near its engaged position than when it is near its disengaged position.

9. A clutch for connecting two shafts comprising a clutch member connected to one of the shafts, a supporting structure connected to'the other of the shafts extending radially outward therefrom, pivot pins on the supporting structure at circumferentially spaced points, a friction shoe and a centrifugal weight pivoted on each of the pins and extending generally circumferentially therefrom, and linkage means connect- 'ing' the weights respectively to shoes pivoted on other pins to move the shoes into engagement with the clutch member as the weights move out in response to centrifugal force whereby the weights create reaction forces on the pins tending to balance the pressure of the shoes thereon.

10. A clutch for connecting two shafts comprising a clutch member connected to one of the shafts, a supporting structure connected to the other of the shafts extending radially outward therefrom, pivot pins on the supporting structure at circumferentially spaced points, a friction shoe and a centrifugal weight pivoted'on each of the pins and extending generally circumferentially therefrom, means connecting each of the weights to a shoe pivoted on a different pin to urge the shoes ino engagement with the clutch member, a spring, and mechanism operatively connecting the spring to the shoes to move the shoes away from the clutch member including a link which changes its angle relative to the shaft axis as the shoes move to give the spring a greater mechanical advantage over the shoes when they are away from the clutch member than when they are adjacent the clutch member.

11. A clutch for connecting two shafts com prising a drum connected to one of the shafts, a supporting plate carried by the other shaft, circumferentially spaced pivot pins on the plate, an arcuate friction shoe and a centrifugal weight pivoted on each of the pins and extending generally circumferentially therefrom in opposite directions, and links connecting the free end portions of the shoes respectively to weights pivoted on different pins whereby the weights actuate the shoes and create reaction forces on the pivot pins tending to balance the pressure of the shoes thereon.

ADIEL Y. DODGE. 

